1. Field of the Invention
The present invention relates to a manually adjustable clutch that may be adjusted without disassembly of the clutch assembly.
2. Background Art
Clutch assemblies are used to control the transmission of torque from an engine to a multiple speed gear transmission. Clutches generally have a plurality of plates with friction engaging surfaces that transmit torque when the clutch plates are compressed and interrupt torque transfer when pressure is released from the clutch plates. All clutches are subject to wear over time and require adjustment to provide a desired clutch engagement position for optimal performance.
Automatically adjusting clutches have been developed that do not require manual adjustment by a mechanic, however, automatically adjusting clutches require complicated mechanical linkages that add cost to the clutch assembly. Automatically adjusting clutches also require additional parts that add weight and may complicate clutch operation.
Manually adjusted clutches may provide the optimal performance associated with a properly adjusted clutch but require periodic manual adjustments. Relative movement between the adjusting ring and clutch cover may change the orientation of a diaphragm spring within the clutch to adjust the clutch. Currently, manually adjusted clutches may have threaded adjusting rings that interface with the threads embedded in the clutch housing. Alternatively, a gear may be provided that engages gear teeth on an inner diameter of an adjusting ring. The gear may be rotated to drive the adjusting ring and turn the adjusting ring relative to the clutch cover on threads provided between the clutch cover and the adjusting ring.
An example of this type of a clutch adjustment mechanism is disclosed in U.S. Pat. No. 4,832,164. The adjustment mechanism described in the '164 patent may be adversely affected by contamination becoming lodged between adjustment component. Also, the adjusting ring can move as a result of inertial forces from engine rotation and engine torsional vibration. If the adjusting ring moves, the clutch may go out of adjustment and require readjustment to maintain optimal performance.
These and other problems and disadvantages are addressed by applicant's invention as summarized below.